The Bonner Sphere Spectrometer consists of an array of He-3 proportional counter thermal neutron detectors, each housed in a spherical HDPE moderator of different diameters.
BSS is proposed in two main configurations, adjustable according to the requirements, for single or multiple detectors.
An unfolding software (RUFUS), used to calculate the neutron spectrum, is also available for both configurations.
Each proportional counter is connected to a compact electronic module (2.5 cm diam. x 7.6 cm), providing:
- Precision wide-band charge-sensitive pre-amplifier and amplifier
- Discriminator circuit
- High voltage adjustment 0-2200 V
- Amplifier gain and discriminator threshold adjustment
- Analogue test points for shaped signals and HV
A user-friendly dedicated acquisition software can be installed on the PC managing the BSS, allowing the user to start and stop the measurements, to modify the parameters and to visualize the saved data.
The BSS standard set, designed to cover the neutron energy range from 1 meV to < 100 MeV, includes the following HDPE moderators: Ø 3”, Ø 3.5”, Ø 4”, Ø 4.5”, Ø 5”, Ø 6”, Ø 7”, Ø 8”, Ø 10”, Ø 12”, Ø 15”, Ø 18”.
The available configurations of BSS are:
- Single detector: includes only one He-3 proportional counter, to be inserted in one moderator sphere at a time. The detector is managed by a Counter Module and the user interface is the “Single counter” software.
- Multiple detectors: includes up to 16 He-3 proportional counters, and up to 16 moderator spheres (12 standard + 4 accessory), to be employed at the same time. The detectors are managed by a Datalogger and the user interface is the “DLOG” software.
